Pilgrims at a shrine in Karbala, a conservative town where locals are being terrorised by sound bombs.

For several weeks now, the people of the southern Iraqi city of Karbala have been tormented by what are described as “sound bombs”. Basically these are devices that make very loud noises when exploded but which tend not to do any physical damage. Lately in Karbala locals have been hearing these deafening bombs every Thursday in certain parts of the city and they have started avoiding going into these areas, because of the sound bombs.

Locals believe the bombs are the work of followers of rebel Shiite Muslim cleric, Mahmoud al-Sarkhi, and that they are being detonated in retaliation for government attacks on al-Sarkhi and his followers, particular in the religious leader’s stronghold in the neighbourhood of Saif Saad.

After army and police entered Saif Saad in early July, al-Sarkhi disappeared from public view but clashes between his supporters and authorities continued, leaving a number of dead and wounded. Al-Sarkhi’s headquarters were also bombed and his home demolished.

Al-Sarkhi came to Karbala after the fall of the Iraqi leader Saddam Hussein due to the US-led invasion of Iraq 2003. He encouraged violence and resistance against US troops and his headquarters were closed down in 2004.

But he did not disappear. In June 2006, al-Sarkhi’s followers attacked the Iranian consulate in Basra due to Iranian criticism of al-Sarkhi and in 2012, they clashed violently with supporters of Shiite Muslim leader, the Grand Ayatollah Ali-al-Sistani, who lives in Karbala. Early in July, al-Sarkhi expressed his support for Sunni Muslims rebelling in Iraq, saying that it had nothing to do with foreigners and everything to do with a popular rebellion.

Karbala is a centre of Shiite Muslim tradition. And as pan-Arab daily, Asharq Al Awsat, reported in July, at the time of the most recent clashes: “There has long been discontent among the Shiite clerical hierarchy towards Sarkhi, one of the youngest clerics to be awarded the title Grand Ayatollah, over his populist fatwas”.

Local clerics told the newspaper that al-Sarkhi’s behaviour contradicted common traditions in Shiite Muslim seminaries where hierarchy is respected. Al-Sarkhi drew the ire of many locals in the conservative town when he condemned a call from al-Sistani for all Iraqis to support the fight against Sunni Muslim extremists from the Islamic State, or IS, group, that was taking over swathes of country in northern Iraq.

After Karbala authorities tried but failed to arrest al-Sarkhi in early July for spreading extremist ideology, they issued an order banning activities by him or his followers. Anyone who violated the order could be prosecuted, they said.

And now, one Karbala cab driver confirms, al-Sarkhi’s followers have barricaded themselves into the Saif Saad area. They have fortified surrounding houses and they’re guarding the area, says Ali Tayeh, a driver who lives in the neighbourhood. They are guarding al-Sarkhi’s religious school and they are not allowing locals to use their own homes or businesses, if these are too nearby.

Haider al-Moussawi, the head of Karbala’s bomb squad, confirmed that there have been explosions in several parts of Karbala. Parking areas around Maytham al-Tammar Street in central Karbala were targeted five times, and each of the explosions happened on a Thursday, in the same place, around the same time.

Al-Moussawi also told NIQASH that the sound bombs were homemade and relatively primitive in terms of their production. The persons who made and exploded the sound bombs put them in rubbish containers and then used remote controls to detonate them, he noted.

The fact that the sound bombs kept going off at the same time and in the same place has become a controversial issue for local security forces. Locals say they are clearly unable to control the area – they know it’s going to happen but they can’t stop it.

Then again nobody really knows who is responsible for these sound bombs. Conspiracy theories abound. Many believe they are due to al-Sarkhi’s supporters. Local man, Uday al-Masoudi, who lives in the Saif Saad area that is home to many al-Sarkhi supporters and his seminary, says that local security forces discovered a factory for making real bombs and sound bombs at al-Sarkhi’s headquarters.

But some also suspect the Sunni Muslim extremists from the IS group.

A local lawyer, Safaa Radi, who firmly believes this, says that members of the organization have managed to get into Karbala disguised as refugees fleeing the IS further north. Local security forces arrested IS fighters trying to get into the city – they had come to do reconnaissance on roads leading into Karbala, Radi says. Radi called upon local security forces to properly investigate the backgrounds of the refugees they were allowing into the province.